1. Field of the Invention
The present invention relates to a conveyor for transporting passengers or objects.
2. Description of the Related Art
FIG. 52 is a plan view of a conventional conveyor capable of moving upward and downward while turning. FIG. 53 is a side elevation view of this conveyor. In these figures, a lower floor and an upper floor are indicated by a and b, respectively. Indicated by c and d are an entrance step and an exit step, respectively. A moving staircase e transports passengers or objects and comprises steps f. The conveyor further includes handrails g and side walls h. The direction of movement of the steps f is changed from a downward direction to an upward direction at the position of the entrance step c and is changed from an upward direction to a downward direction at the position of the exit step d. The steps are driven to circulate along such a path.
FIG. 54 is a perspective view of one of the steps f. FIG. 55 is a plan view of the step shown in FIG. 54. FIG. 56 is a front elevation view of the step. FIG. 57 is a side elevation view of the step. In these figures, the step is turned about a point 0. As can be seen from these figures, in the conventional conveyor, the path of conveyance is uniquely determined by the shape of the steps, because the steps are designed according to the radius of curvature of the path of conveyance.
An attempt was made to realize a path of conveyance by combining arbitrary curves irrespective of the shape of steps. FIG. 58 is a plan view of a moving staircase of this kind, and in which individual steps are indicated by k. When some neighboring steps k of this moving staircase travel around a curve, they overlap with each other.
In the prior art conveyor, the turning radius of the path of conveyance is set to a certain value according to the shape of the steps. Further, the turning radius must be previously determined and cannot be changed. Therefore, it has been impossible to realize a conveyor which can travel along a curvilinear and vertically movable path of conveyance defined by an arbitrary combination of straight lines and curves.
As the steps convey passengers or objects, they are exposed on the upper surface of the path of conveyance. At one end of the conveyor, they shift to the lower side of the path of conveyance and then move on. At the other end, they again shift to the upper side of the path of conveyance and convey passengers or objects. In this reversing and circulating system, those steps which are moving on the lower side are not used to convey passengers or objects and so it follows that these steps make wasteful movement.
In the moving staircase shown in FIG. 58, when some adjacent steps k travel around a curve, they overlap with each other, thus causing inconvenience to the passengers.